Designed in 1934 in response to a Spanish Air Force requirement as part of its modernisation programme, the Chirta was a conventional sesquiplane, constructed of wood and metal and seating the student and instructor in tandem open cockpits. Slightly tapered wings had ailerons only on the upper wings; unusually, these covered the full span. Fuel was carried in an upper wing tank. There was a cut-out in the trailing edge of the upper wing for better upward visibility from the rear seat; the front seat was under the wing. A triangular fin carried a slightly rounded, unbalanced rudder. The tailskid undercarriage had faired wheels on V-form main legs. The Chirta was intended to undertake fighter training and to be fully aerobatic.[1]

Though the exact date of the first flight of the Chirta is not known, by early July 1935 it was flying and sufficiently developed to have taken part in competitive trials for the trainer contract.[2] It was evaluated against the Gil-Pazó GP-1 and Hispano E-34 but was ranked third,[2] so no production contract was awarded. No further examples were built, though the prototype survived undamaged until at least November 1936, when Francoist forces captured Cuatro Vientos, where the trials had taken place.[1]

1.
Trainer (aircraft)
–
A trainer is a class of aircraft designed specifically to facilitate flight training of pilots and aircrews. Civilian pilots are trained in a light aircraft, with two or more seats to allow for a student and instructor. The aircraft may be modified to withstand the conditions imposed by training flights. The two seating configurations for trainer aircraft are, pilot and instructor side by side, or in tandem, usually with the pilot in front, the tandem configuration has the advantage of being closer to the normal working environment that a fast jet pilot is likely to encounter. It is now the norm for pilots to begin their training in an aircraft with side by side seating. This, however, has not always been the case, given the expense of military pilot training, air forces typically conduct training in phases to eliminate unsuitable candidates. The cost to air forces that do not follow a graduated training regimen is not just monetary. There are two areas for instruction, flight training and operational training. In flight training a candidate seeks to develop their flying skills, in operational training the candidate learns to use his or her flying skills through simulated combat, attack and fighter techniques. Typically, contemporary military pilots learn initial flying skills in an aircraft not too dissimilar from civilian training aircraft. In this phase candidates are screened for mental and physical attributes. Aircraft used for this include the Slingsby Firefly, as at one time used by the United States Air Force Academy. The U. S. replaced the Firefly and the Enhanced Flight Screen Program with the Diamond DA20, at the end of this stage, pilot trainees are assessed as to where their attributes lie, as fast jet, multi-engine or rotary wing pilots. Those who are judged unsuitable for a commission, but show other attributes, may be offered the chance to qualify as navigators. Smaller and more financially restricted air forces may use ultra-light aircraft, gliders, after the ab-inito phase a candidate may progress to basic, or primary, trainers. These are usually turboprop trainers, like the Pilatus PC-9 and Embraer Tucano, prior to the availability of high performance turboprops, basic training was conducted with jet aircraft such as the BAC Jet Provost, T-37 Tweet, and Fouga Magister. Those candidates who are not suitable to continue training as fast jet pilots may be offered flying commissions, examples of such jet trainer aircraft include the supersonic T-38 Talon, the BAE Hawk, the Dassault/Dornier Alpha Jet, the Aero L-39 and the Yakovlev Yak-130. Effective combat aircraft are a function now electronics as much as, if not more so than and it is at this stage that a pilot begins to learn to operate radar systems and electronics

2.
Spain
–
By population, Spain is the sixth largest in Europe and the fifth in the European Union. Spains capital and largest city is Madrid, other urban areas include Barcelona, Valencia, Seville, Bilbao. Modern humans first arrived in the Iberian Peninsula around 35,000 years ago, in the Middle Ages, the area was conquered by Germanic tribes and later by the Moors. Spain is a democracy organised in the form of a government under a constitutional monarchy. It is a power and a major developed country with the worlds fourteenth largest economy by nominal GDP. Jesús Luis Cunchillos argues that the root of the span is the Phoenician word spy. Therefore, i-spn-ya would mean the land where metals are forged, two 15th-century Spanish Jewish scholars, Don Isaac Abravanel and Solomon ibn Verga, gave an explanation now considered folkloric. Both men wrote in two different published works that the first Jews to reach Spain were brought by ship by Phiros who was confederate with the king of Babylon when he laid siege to Jerusalem. This man was a Grecian by birth, but who had given a kingdom in Spain. He became related by marriage to Espan, the nephew of king Heracles, Heracles later renounced his throne in preference for his native Greece, leaving his kingdom to his nephew, Espan, from whom the country of España took its name. Based upon their testimonies, this eponym would have already been in use in Spain by c.350 BCE, Iberia enters written records as a land populated largely by the Iberians, Basques and Celts. Early on its coastal areas were settled by Phoenicians who founded Western Europe´s most ancient cities Cadiz, Phoenician influence expanded as much of the Peninsula was eventually incorporated into the Carthaginian Empire, becoming a major theater of the Punic Wars against the expanding Roman Empire. After an arduous conquest, the peninsula came fully under Roman Rule, during the early Middle Ages it came under Germanic rule but later, much of it was conquered by Moorish invaders from North Africa. In a process took centuries, the small Christian kingdoms in the north gradually regained control of the peninsula. The last Moorish kingdom fell in the same year Columbus reached the Americas, a global empire began which saw Spain become the strongest kingdom in Europe, the leading world power for a century and a half, and the largest overseas empire for three centuries. Continued wars and other problems led to a diminished status. The Napoleonic invasions of Spain led to chaos, triggering independence movements that tore apart most of the empire, eventually democracy was peacefully restored in the form of a parliamentary constitutional monarchy. Spain joined the European Union, experiencing a renaissance and steady economic growth

3.
Spanish Civil War
–
Ultimately, the Nationalists won, and Franco then ruled Spain for the next 36 years, from April 1939 until his death in November 1975. Sanjurjo was killed in an accident while attempting to return from exile in Portugal. The coup was supported by units in the Spanish protectorate in Morocco, Pamplona, Burgos, Zaragoza, Valladolid, Cádiz, Córdoba. However, rebelling units in some important cities—such as Madrid, Barcelona, Valencia, Bilbao, and Málaga—did not gain control, Spain was thus left militarily and politically divided. The Nationalists and the Republican government fought for control of the country, the Nationalist forces received munitions and soldiers from Nazi Germany and Fascist Italy, while the Republican side received support from the Communist Soviet Union and leftist populist Mexico. Other countries, such as the United Kingdom and France, operated a policy of non-intervention. The Nationalists advanced from their strongholds in the south and west and they also besieged Madrid and the area to its south and west for much of the war. Those associated with the losing Republicans were persecuted by the victorious Nationalists, with the establishment of a dictatorship led by General Franco in the aftermath of the war, all right-wing parties were fused into the structure of the Franco regime. The war became notable for the passion and political division it inspired, organized purges occurred in territory captured by Francos forces to consolidate the future regime. A significant number of killings took place in areas controlled by the Republicans, the extent to which Republican authorities took part in killings in Republican territory varied. The 19th century was a turbulent time for Spain and those in favour of reforming Spains government vied for political power with conservatives, who tried to prevent reforms from taking place. Some liberals, in a tradition that had started with the Spanish Constitution of 1812, sought to limit the power of the monarchy of Spain, the reforms of 1812 did not last after King Ferdinand VII dissolved the Constitution and ended the Trienio Liberal government. Twelve successful coups were carried out between 1814 and 1874, until the 1850s, the economy of Spain was primarily based on agriculture. There was little development of an industrial or commercial class. The land-based oligarchy remained powerful, a number of people held large estates called latifundia as well as all the important government positions. In 1868 popular uprisings led to the overthrow of Queen Isabella II of the House of Bourbon, two distinct factors led to the uprisings, a series of urban riots and a liberal movement within the middle classes and the military concerned with the ultra-conservatism of the monarchy. In 1873 Isabellas replacement, King Amadeo I of the House of Savoy, abdicated owing to increasing pressure. After the restoration of the Bourbons in December 1874, Carlists and Anarchists emerged in opposition to the monarchy, alejandro Lerroux, Spanish politician and leader of the Radical Republican Party, helped bring republicanism to the fore in Catalonia, where poverty was particularly acute

4.
Spanish Air Force
–
The Spanish Air Force is the aerial branch of the Spanish Armed Forces. Hot air balloons had been used with military purposes in Spain as far back as 1896, the new airship was completed successfully and, named España, made numerous test and exhibition flights. One year later a Royal decree established the National Aviation School, Escuela Nacional de Aviación in Getafe, near Madrid, under the Ministry of Public Works and Transport, captain Alfredo Kindelán was named Chief of Aviation, Jefe de Aviación. During the years followed, most of the military activity of the Spanish Air Force would take place in Northern Morocco. In 1915 Spains first seaplane base was opened at Los Alcazares on the Mar Menor in the Murcia region and Alfredo Kindelán was named Military Aeronautics Director, the Catalan Flying School was established in Can Tunis, Barcelona the following year and Getafe Aerodrome became a full-fledged military air base. In 1919 General Francisco Echagüe replaced Kindelán as leader of the Aeronáutica Española, in 1920 two Nieuport 80 and one Caudron G.3 were first painted with squadron identification numbers and the Spanish Air Force roundel. In 1921, following the Spanish defeat at Annual, known as Desastre de Annual in Spain, Lieutenant Colonel Kindelán was named Jefe Superior de Aeronáutica, becoming chief-commander of the air force in 1926, at the time when Spanish Morocco was retaken and the Rif War ended. That same year, pilots González Gallarza, Joaquín Loriga Taboada, the expedition was flown with two Breguet 19 and known as the Escuadrilla Elcano or Elcano Squadron. In 1930 the Aeronaval Base in San Javier was established and in the year a pro-Republican revolt in the Cuatro Vientos military aerodrome near Madrid was quashed. Captain Cipriano Rodríguez Díaz and Lieutenant Carlos de Haya González flew non-stop to Equatorial Guinea, under Capitan Warlela cadastral surveys of Spain were carried out using modern methods of aerial photography in 1933. The following year Spanish engineer Juan de la Cierva took off, in 1934 Commander Eduardo Sáenz de Buruaga became new chief-commander of the air force. Accordingly, the Spanish Navy-based Escuadra model was replaced by Región Militar divisions which are still operative today. In July 1936, right after the coup, the first German Junkers Ju-52 and Italian Savoia-Marchetti SM.81 arrived to help the rebels, in August Heinkel He 51 fighters were also deployed. These planes helped the army in revolt to gain control of the air, as did the German and Italian expeditionary forces, the Condor Legion. In September 1936 the Navy and Air Ministry, Ministerio de Marina y Aire, the first serious air combat took place over Madrid when Italian bombers attacked the city in a massive bombing operation. Nazi help to the Nationalist Air Force was part of Hitlers German re-armament strategy and he called his strategy Blumenkrieg, as evidenced in a January 1937 speech. The international outcry over Guernica, however, would not bring about any increase in the help provided to the beleaguered Spanish Republic. The pilots of the Spanish Republican Air Force, often young and poorly trained were unable to check the Nazi German and Fascist Italian modern-warfare attacks

5.
Sesquiplane
–
A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, while a biplane wing structure has a structural advantage over a monoplane, it produces more drag than a similar unbraced or cantilever monoplane wing. Improved structural techniques, better materials and the quest for greater speed made the biplane configuration obsolete for most purposes by the late 1930s. Biplanes offer several advantages over conventional cantilever monoplane designs, they permit lighter wing structures, low wing loading, however, interference between the airflow over each wing increases drag substantially, and biplanes generally need extensive bracing, which causes additional drag. Biplanes are distinguished from tandem wing arrangements, where the wings are placed forward and aft, instead of above, the term is also occasionally used in biology, to describe the wings of some flying animals. In a biplane aircraft, two wings are placed one above the other, either or both of the main wings can support ailerons, while flaps are more usually positioned on the lower wing. Bracing is nearly always added between the upper and lower wings, in the form of wires and/or slender interplane struts positioned symmetrically on either side of the fuselage. The primary advantage of the biplane over the traditional single plane or monoplane is to combine great stiffness with light weight. A braced monoplane wing must support itself fully, while the two wings of a help to stiffen each other. The biplane is therefore inherently stiffer than the monoplane, also, the structural forces in the spars of a biplane wing tend to be lower, so the wing can use less material to obtain the same overall strength and is therefore much lighter. A disadvantage of the biplane was the need for extra struts to space the wings apart, the low power supplied by the engines available in the first years of aviation meant that aeroplanes could only fly slowly. This required an even lower stalling speed, which in turn required a low wing loading, combining both large wing area with light weight. A biplane wing of a span and chord has twice the area of a monoplane the same size and so can fly more slowly. Alternatively, a wing of the same area as a monoplane has lower span and chord, reducing the structural forces. Biplanes suffer aerodynamic interference between the two planes and this means that a biplane does not in practice obtain twice the lift of the similarly-sized monoplane. The farther apart the wings are spaced the less the interference, given the slow speed and low power of early aircraft, the drag penalty of the wires and struts and the mutual interference of airflows were relatively minor and acceptable factors. The smaller biplane wing also allows greater maneuverability, during World War One, this further enhanced the dominance of the biplane and, despite the need for speed, military aircraft were among the last to abandon the biplane form. Specialist sports Aerobatic biplanes are still occasionally made, biplanes were originally designed with the wings positioned directly one above the other

6.
Ailerons
–
An aileron is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll, movement around this axis is called rolling or banking. The aileron was first patented by the British scientist and inventor Matthew Piers Watt Boulton in 1868, considerable litigation ensued within the United States over the legal issues of lateral roll control, until World War I which compelled the U. S. Government to legislate a legal resolution. The name aileron, from French, meaning wing, also refers to the extremities of a birds wings used to control their flight. It first appeared in print in the 7th edition of Cassells French-English Dictionary of 1877, in the context of powered airplanes it appears in print about 1908. Prior to that, ailerons were often referred to as rudders, their older technical sibling, among the earliest printed aeronautical use of aileron was that in the French aviation journal LAérophile of 1908. He was the first to patent an aileron control system in 1868, Boultons description of his lateral flight control system was both clear and complete. It was the first record we have of appreciation of the necessity for active lateral control as distinguished from, with this invention of Boultons we have the birth of the present-day three torque method of airborne control as was praised by Charles Manly. This was also endorsed by C. H, the fact that the Wright brothers were able to gain a patent in 1906 did not invalidate Boultons lost and forgotten invention. The pioneering U. S. aeronautical engineer Octave Chanute published descriptions and drawings of the Wright brothers 1902 glider in the leading periodical of the day, LAérophile. This prompted Esnault-Pelterie, a French military engineer, to build a Wright-style glider in 1904 that used ailerons in lieu of wing warping. The French journal L’Aérophile then published photos of the ailerons on Esnault-Pelterie’s glider which were included in his June 1905 article, during the early years of powered flight the Wrights had better roll control on their designs than airplanes that used movable surfaces. From 1908, as aileron designs were refined it became clear that ailerons were much more effective, ailerons also had the advantage of not weakening the airplanes wing structure as did the wing warping technique, which was one reason for Esnault-Pelteries decision to switch to ailerons. By 1911 most biplanes used ailerons rather than wing warping - by 1915 ailerons had become almost universal on monoplanes as well, the Wright brothers quietly changed their aircraft flight controls from wing warping to the use of ailerons at that time as well. In 1886 his third glider design used rotation of the wing rather than just a trailing edge portion for roll control. By his own all of these changes in addition to his use of an elevator for pitch control provided entire control of the machine in the wind. Both Bullet prototypes crashed during their first flights when their wings broke off in flight due to flutter as a result of being deliberately unbraced. S, the patents importance lay in its claim of a new and useful method of controlling an airplane. Curiously, John J. Montgomery was granted U. S, Patent 831173 at nearly the same time for his methods of wing warping

7.
Fin
–
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, fins are also used to increase surface areas for heat transfer purposes, or simply as ornamentation. Fins first evolved on fish as a means of locomotion, Fish fins are used to generate thrust and control the subsequent motion. Fish, and other animals such as cetaceans, actively propel and steer themselves with pectoral. As they swim, they use other fins, such as dorsal and anal fins to achieve stability, foil shaped fins generate thrust when moved, the lift of the fin sets water or air in motion and pushes the fin in the opposite direction. Aquatic animals get significant thrust by moving back and forth in water. Often the tail fin is used, but some aquatic animals generate thrust from pectoral fins, fins can also generate thrust if they are rotated in air or water. Turbines and propellers use a number of rotating fins, also called foils, wings, propellers use the fins to translate torquing force to lateral thrust, thus propelling an aircraft or ship. Turbines work in reverse, using the lift of the blades to generate torque, cavitation can be a problem with high power applications, resulting in damage to propellers or turbines, as well as noise and loss of power. Cavitation occurs when negative pressure causes bubbles to form in a liquid and it can cause significant damage and wear. Cavitation damage can occur to the tail fins of powerful swimming marine animals, such as dolphins. Cavitation is more likely to occur near the surface of the ocean, even if they have the power to swim faster, dolphins may have to restrict their speed because collapsing cavitation bubbles on their tail are too painful. Cavitation also slows tuna, but for a different reason, unlike dolphins, these fish do not feel the bubbles, because they have bony fins without nerve endings. Nevertheless, they cannot swim faster because the cavitation bubbles create a film around their fins that limits their speed. Lesions have been found on tuna that are consistent with cavitation damage, scombrid fishes are particularly high-performance swimmers. Along the margin at the rear of their bodies is a line of small rayless, non-retractable fins, there has been much speculation about the function of these finlets. Fish use multiple fins, so it is possible that a given fin can have an interaction with another fin. In particular, the fins immediately upstream of the fin may be proximate fins that can directly affect the flow dynamics at the caudal fin

8.
Balanced rudder
–
Balanced rudders are used by both ships and aircraft. Both may indicate a portion of the surface ahead of the hinge. For aircraft the method can also be applied to elevators and ailerons, a balanced rudder is a rudder in which the axis of rotation of the rudder is behind its front edge. A degree of semi-balance is normal to avoid rudder instability i. e. the area in front of the pivot is less than that behind and this allows the rudder to be moved with less effort than is necessary with an unbalanced rudder. The balanced rudder was invented by Isambard Kingdom Brunel and first used on the SS Great Britain and this is referred to as aerodynamical balance. This is called mass balancing The principle is used on rudders, elevators and ailerons, two illustrations of aircraft rudders, published by Flight Magazine in 1920, illustrate early forms, both with curved leading and trailing edges. Both are mounted so that the area of the surface ahead of the hinge is less than that of the rudder behind. Various layouts have been tried over the years, generally with smaller balance/rudder areas, frise ailerons use a variant of the latter balance, with the nose of the up-going surface projecting below the wing, but not vice versa, to provide both balancing and asymmetric drag. Irving balanced ailerons have no projections but harness the aileron deflection induced change of pressure above and below the wing, sensed via the hinge gap, flutter occurs when the control surface is displaced from its intended deflection. Because the ailerons are on the long, narrow wings which can twist under load, if the centre of gravity is behind the hinge, the surface can move like a pendulum and undergo forced simple harmonic motion with increasing amplitude. Adding balancing weights which make the centre of gravity and hinge line coincident solves the problem and these weights may be in the nose of the surface, or lighter masses attached further ahead of the hinge externally

9.
Aircraft fairing
–
An aircraft fairing is a structure whose primary function is to produce a smooth outline and reduce drag. These structures are covers for gaps and spaces between parts of an aircraft to form drag and interference drag, and to improve appearance. On aircraft, fairings are commonly found on, Cockpit fairing Also called a cockpit pod, commonly made from fiberglass, it may also incorporate a windshield. Elevator and horizontal stabilizer tips Elevator and stabilizer tips fairings smooth out airflow at the tips, the inlet and the nozzle in combination lead to an isotropic speed reduction around the cooling fins and due to the speed-squared law to a reduction in cooling drag. Fin and rudder tips fairings reduce drag at low angles of attack, fillets smooth the airflow at the junction between two components like fuselage and wing, or fuselage and fin. Fixed landing gear junctions Landing gear fairings reduce drag at these junctions, flap track fairings Most jet airliners have a cruising speed between Mach 0.8 and 0.85. For aircraft operating in the regime, wave drag can be minimized by having a cross-sectional area which changes smoothly along the length of the aircraft. This is known as the area rule, on subsonic aircraft such as jet airliners, this can be achieved by the addition of smooth pods on the trailing edges of the wings. These pods are known as anti-shock bodies, Küchemann Carrots, or flap track fairings, spinner To cover and streamline the propeller hub. Strut-to-wing and strut-to-fuselage junctions Strut end fairings reduce drag at these junctions, Tail cones Tail cones reduce the form drag of the fuselage, by recovering the pressure behind it. For the design speed they add no friction drag, Wing root Wing roots are often faired to reduce interference drag between the wing and the fuselage. On top and below the wing it consists of small rounded edge to reduce the surface, Wing tips Wing tips are often formed as complex shapes to reduce vortex generation and so also drag, especially at low speed. Wheels on fixed gear aircraft Wheel fairings are often called wheel pants, speed fairings or, in the UK and they also have the important function of preventing mud and stones from being thrown upwards against the wings or fuselage, or into the propeller on a pusher craft. Bicycle fairing Motorcycle fairing Payload fairing

10.
Walter Junior
–
The Walter Minor is a family of four- and six-cylinder inverted inline air-cooled engines, developed under auspices of ing. Šimůnek and used on light aircraft, typical power ratings varied from 105 hp to 160 hp. Nowadays the smallest of the family, the four-cylinder carburetted Minor, is produced by a company in the Czech Republic

11.
V speeds
–
In aviation, V-speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft. Using them is considered a best practice to maximize aviation safety, the actual speeds represented by these designators are specific to a particular model of aircraft. They are expressed by the indicated airspeed, so that pilots may use them directly, without having to apply correction factors. In general aviation aircraft, the most commonly used and most safety-critical airspeeds are displayed as color-coded arcs, the lower ends of the green arc and the white arc are the stalling speed with wing flaps retracted, and stalling speed with wing flaps fully extended, respectively. These are the speeds for the aircraft at its maximum weight. The yellow range is the range in which the aircraft may be operated in air, and then only with caution to avoid abrupt control movement, and the red line is the Vne. Proper display of V speeds is a requirement for type-certificated aircraft in most countries. The most common V-speeds are often defined by a particular governments aviation regulations, in the United States, these are defined in title 14 of the United States Code of Federal Regulations, known as the Federal Aviation Regulations or FARs. In Canada, the body, Transport Canada, defines 26 commonly used V-speeds in their Aeronautical Information Manual. V-speed definitions in FAR23,25 and equivalent are for designing and certification of airplanes, the descriptions below are for use by pilots. These V-speeds are defined by regulations and they are typically defined with constraints such as weight, configuration, or phases of flight, some of these constraints have been omitted to simplify the description. Some of these V-speeds are specific to types of aircraft and are not defined by regulations. Whenever a limiting speed is expressed by a Mach number, it is expressed relative to the speed of sound, e. g. VMO, Maximum operating speed, MMO, V1 is the critical engine failure recognition speed or takeoff decision speed. It is the speed above which the takeoff will continue if a engine fails or another problem occurs. Aborting a takeoff after V1 is strongly discouraged because the aircraft will by definition not be able to stop before the end of the runway, Transport Canada defines it as, Critical engine failure recognition speed and adds, This definition is not restrictive. An operator may adopt any other definition outlined in the flight manual of TC type-approved aircraft as long as such definition does not compromise operational safety of the aircraft. Getting to grips with aircraft performance, flight Operations Support & Line Assistance

12.
International Standard Book Number
–
The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning an ISBN is nation-based and varies from country to country, often depending on how large the publishing industry is within a country. The initial ISBN configuration of recognition was generated in 1967 based upon the 9-digit Standard Book Numbering created in 1966, the 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108. Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure, however, this can be rectified later. Another identifier, the International Standard Serial Number, identifies periodical publications such as magazines, the ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker and in 1968 in the US by Emery Koltay. The 10-digit ISBN format was developed by the International Organization for Standardization and was published in 1970 as international standard ISO2108, the United Kingdom continued to use the 9-digit SBN code until 1974. The ISO on-line facility only refers back to 1978, an SBN may be converted to an ISBN by prefixing the digit 0. For example, the edition of Mr. J. G. Reeder Returns, published by Hodder in 1965, has SBN340013818 -340 indicating the publisher,01381 their serial number. This can be converted to ISBN 0-340-01381-8, the check digit does not need to be re-calculated, since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland European Article Number EAN-13s. An ISBN is assigned to each edition and variation of a book, for example, an ebook, a paperback, and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, a 13-digit ISBN can be separated into its parts, and when this is done it is customary to separate the parts with hyphens or spaces. Separating the parts of a 10-digit ISBN is also done with either hyphens or spaces, figuring out how to correctly separate a given ISBN number is complicated, because most of the parts do not use a fixed number of digits. ISBN issuance is country-specific, in that ISBNs are issued by the ISBN registration agency that is responsible for country or territory regardless of the publication language. Some ISBN registration agencies are based in national libraries or within ministries of culture, in other cases, the ISBN registration service is provided by organisations such as bibliographic data providers that are not government funded. In Canada, ISBNs are issued at no cost with the purpose of encouraging Canadian culture. In the United Kingdom, United States, and some countries, where the service is provided by non-government-funded organisations. Australia, ISBNs are issued by the library services agency Thorpe-Bowker

Trainer (aircraft)
–
A trainer is a class of aircraft designed specifically to facilitate flight training of pilots and aircrews. Civilian pilots are trained in a light aircraft, with two or more seats to allow for a student and instructor. The aircraft may be modified to withstand the conditions imposed by training flights. The two seating configurations for trainer a

1.
Slingsby T-67 Firefly of the UK Defence Elementary Flying Training School, used for training army and navy pilots

2.
Cockpit of the Aermacchi SF.260. Student pilot or PIC in the right-hand seat, where all primary flight instrument are.

3.
HAL HJT-36 jet trainer that is set to replace the HAL Kiran aircraft of the Indian Air Force, together with the HAL Tejas.

4.
Polish 3Xtrim 3X55 Trener ultralight trainer

Spain
–
By population, Spain is the sixth largest in Europe and the fifth in the European Union. Spains capital and largest city is Madrid, other urban areas include Barcelona, Valencia, Seville, Bilbao. Modern humans first arrived in the Iberian Peninsula around 35,000 years ago, in the Middle Ages, the area was conquered by Germanic tribes and later by t

1.
Lady of Elche

2.
Flag

3.
Altamira Cave paintings, in Cantabria.

4.
Celtic castro in A Guarda, Galicia.

Spanish Civil War
–
Ultimately, the Nationalists won, and Franco then ruled Spain for the next 36 years, from April 1939 until his death in November 1975. Sanjurjo was killed in an accident while attempting to return from exile in Portugal. The coup was supported by units in the Spanish protectorate in Morocco, Pamplona, Burgos, Zaragoza, Valladolid, Cádiz, Córdoba. H

1.
Republican International Brigadiers at the Battle of Belchite ride on a T-26 tank

2.
King Amadeo I of Spain

3.
Republican volunteers at Teruel, 1936.

4.
Republican troops at Guadalajara, 1937

Spanish Air Force
–
The Spanish Air Force is the aerial branch of the Spanish Armed Forces. Hot air balloons had been used with military purposes in Spain as far back as 1896, the new airship was completed successfully and, named España, made numerous test and exhibition flights. One year later a Royal decree established the National Aviation School, Escuela Nacional

Sesquiplane
–
A biplane is a fixed-wing aircraft with two main wings stacked one above the other. The first powered, controlled aeroplane to fly, the Wright Flyer, used a biplane wing arrangement, while a biplane wing structure has a structural advantage over a monoplane, it produces more drag than a similar unbraced or cantilever monoplane wing. Improved struct

1.
Reproduction of a Sopwith Camel biplane.

2.
The Antonov An-2 is the largest single-engine biplane design and has the longest production history of any aircraft, except for the C 130.

3.
Biplane hang glider under tow. Philadelphia, USA, 1920s.

4.
Zeppelin-Lindau D.I strutless biplane

Ailerons
–
An aileron is a hinged flight control surface usually forming part of the trailing edge of each wing of a fixed-wing aircraft. Ailerons are used in pairs to control the aircraft in roll, movement around this axis is called rolling or banking. The aileron was first patented by the British scientist and inventor Matthew Piers Watt Boulton in 1868, co

4.
A 1912 Farman HF.20 biplane with single acting ailerons hinged from the rear spar. The ailerons hang down when at rest and are pushed up into position when flying by the force of the air, being pulled down by cable to provide control.

Fin
–
A fin is a thin component or appendage attached to a larger body or structure. Fins typically function as foils that produce lift or thrust, or provide the ability to steer or stabilize motion while traveling in water, air, fins are also used to increase surface areas for heat transfer purposes, or simply as ornamentation. Fins first evolved on fis

1.
Fish get thrust moving vertical tail fins from side to side

2.
Fins typically function as foils that provide lift or thrust, or provide the ability to steer or stabilize motion in water or air

3.
Cetaceans get thrust moving horizontal tail fins up and down

4.
Stingrays get thrust from large pectoral fins

Balanced rudder
–
Balanced rudders are used by both ships and aircraft. Both may indicate a portion of the surface ahead of the hinge. For aircraft the method can also be applied to elevators and ailerons, a balanced rudder is a rudder in which the axis of rotation of the rudder is behind its front edge. A degree of semi-balance is normal to avoid rudder instability

Aircraft fairing
–
An aircraft fairing is a structure whose primary function is to produce a smooth outline and reduce drag. These structures are covers for gaps and spaces between parts of an aircraft to form drag and interference drag, and to improve appearance. On aircraft, fairings are commonly found on, Cockpit fairing Also called a cockpit pod, commonly made fr

1.
The wing root of a simple aircraft, an American Aviation AA-1 Yankee, showing a wing root fairing.

2.
A cockpit fairing or "pod" with a windshield on a P&M GT450 ultralight trike.

Walter Junior
–
The Walter Minor is a family of four- and six-cylinder inverted inline air-cooled engines, developed under auspices of ing. Šimůnek and used on light aircraft, typical power ratings varied from 105 hp to 160 hp. Nowadays the smallest of the family, the four-cylinder carburetted Minor, is produced by a company in the Czech Republic

1.
Minor

2.
Walter Minor 4-III

V speeds
–
In aviation, V-speeds are standard terms used to define airspeeds important or useful to the operation of all aircraft. Using them is considered a best practice to maximize aviation safety, the actual speeds represented by these designators are specific to a particular model of aircraft. They are expressed by the indicated airspeed, so that pilots

International Standard Book Number
–
The International Standard Book Number is a unique numeric commercial book identifier. An ISBN is assigned to each edition and variation of a book, for example, an e-book, a paperback and a hardcover edition of the same book would each have a different ISBN. The ISBN is 13 digits long if assigned on or after 1 January 2007, the method of assigning

1.
A 13-digit ISBN, 978-3-16-148410-0, as represented by an EAN-13 bar code